Measurement of full-thickness macular hole size using en face optical coherence tomography.

PurposeTo assess the feasibility and interest of measuring macular hole (MH) size using en face optical coherence tomography (OCT) compared with manual diameter measurements on B-scans.MethodsAmong our previously published series of 100 patients operated for primary MH, patients whose images were acquired with Cirrus 5000 HD-OCT (Carl Zeiss Meditec) with a quality signal strength >5/10 were included. Three segmentations (internal limiting membrane, horizontal, and retinal pigment epithelium (RPE)) were compared for obtaining the most appropriate en face image. MH surface areas were measured using ImageJ software. Mean diameters calculated from surface areas (diameter=2 × âˆš(surface area/π)) were compared with those measured on B-scans.ResultsNineteen patients were included with a mean age of 72±8 years (56-86) and a female predominance (3/16). The mean absolute difference between horizontal and vertical diameters measured on B-scans was of 54±47 µm (0-180) without reaching significance (P=0.874). RPE segmentation provided the best en face image and was feasible without and with adjustment, respectively, in 79% and 100% (cases with vitreomacular traction) of cases. No significant difference in mean diameters was observed between those calculated from en face images (435±143 µm (195-693)) and those measured on horizontal B-scans (426±139 µm (214-705), P=0.482).ConclusionMeasuring MH size on en face OCT images is feasible, reliable, and eliminates the potential bias related to manual measurements on B-scans. Its integration into OCT devices would offer an automated and easy-to-use option for clinical practice.

[A "fast track" to improve management of neovascular age related macular degeneration]. / Un « circuit court ¼ pour améliorer la prise en charge des patients atteints de dégénérescence maculaire liée à l'âge néovasculaire.

OBJECTIVE: To evaluate the role of a fast track for management of patients with neovascular age- related macular degeneration (nARMD) treated by intravitreal injection of anti-VEGF. PATIENTS: The records of 100 patients in the chronic maintenance phase of intravitreal anti-VEGF followed in the fast track and 63 patients followed in the standard protocol for at least 12 months were retrospectively analyzed. METHOD: Patients in the fast track underwent visual acuity (VA) testing by ETDRS, optical coherence tomography (OCT) and a physician assessment. The injection was performed the same day whenever possible. The primary endpoint to evaluate patient adherence was the time between the ideal date of visit or injection prescribed by the physician and the actual date of administration. RESULTS: The mean time between the ideal date of visit or injection prescribed by the physician and the actual date of administration was 4.1±7.5 days for the patients followed in the fast track and 5.6±18.7 days for the patients followed in the standard protocol. Mean VA remained stable for the patients followed in the fast track: 20/50 (20/800 to 20/20) at baseline vs. 20/50 (20/800 to 20/16) at the conclusion of follow-up. It dropped from 40/50 at baseline to 20/63 at the conclusion of follow-up for the patients followed in the standard protocol. CONCLUSION: In the context of a fast track, it was possible to improve the adherence of nARMD patients and maintain their VA gain or stabilization achieved after the induction phase.

Efficacy of 0.2 µg/day fluocinolone acetonide implant (ILUVIEN) in eyes with diabetic macular edema and prior vitrectomy.

PurposeLimited data are available on the efficacy of the 0.2 µg/day fluocinolone acetonide (FAc) implant in eyes with prior vitrectomy. Here, we present a collection of 26 vitrectomized eyes treated with the 0.2 µg/day FAc implant.MethodsRetrospective study involving six centers from four European countries analyzing the safety and efficacy data from patients (26 eyes from 25 patients) with DME and a prior vitrectomy that had been treated with one 0.2 µg/day FAc implant.ResultsPrior intravitreal therapies included anti-VEGF (mean, 3.8 injections) and steroids (mean, 1.9 injections). Pars plana vitrectomy (PPV) was performed in these eyes primarily for abnormalities of vitreoretinal interface, followed by proliferative diabetic retinopathy and vitreous hemorrhage. The 0.2 µg/day FAc implant was injected 24.2 months, on average, after PPV and the mean duration of follow-up after injection was 255 days (range, 90 to 759 days). The mean change in BCVA was +11.7 ETDRS letters (range, -19 to +40 letters; P<0.0004) and the mean change in central foveal thickness (CFT) was -233.5 µm (range, -678 to 274 µm; P<0.0001). The mean change in IOP from baseline at the last visit was +1.4 mm Hg (range, -9 to +8 mm Hg; P=0.0090). Eight eyes initiated or continued IOP lowering medications.ConclusionsThese data suggest the 0.2 µg/day FAc implant is effective in vitrectomized patients with an acceptable safety profile. Further studies are still required to confirm the current findings and to assess the effect of the 0.2 µg/day FAc implant over a longer period of follow-up.

Microvascular retinal abnormalities in acute intracerebral haemorrhage and lacunar infarction.

BACKGROUND: Retinal microvascular changes have been previously associated with cerebral MRI markers of small vessel disease (SVD). Whether retinal changes differ between patient with intracerebral haemorrhage (ICH) and patients with lacunar infarction (LI) caused by small vessel disease has been poorly investigated. OBJECTIVE: The study aims to compare the frequency of retinal changes between patients with LI and patients with ICH at the acute stage of stroke-related SVD. METHODS: Microvascular wall signs (arteriolar occlusion, arteriovenous nicking, focal arterial narrowing) and retinopathy lesions (microanevrysms, cotton wool spots, retinal haemorrhages, hard exudates) were assessed by retinography up to three months after stroke onset. RESULTS: Forty-eight non-diabetic patients with acute stroke-related to SVD (26 LI, 22 ICH) were recruited prospectively in the study. Retinal wall signs (arteriovenous nicking, and focal arterial narrowing) were found in more than three quarters of subjects and most often bilaterally in both groups. Retinopathy lesions (cotton wool spots, retinal haemorrhages) were found more frequently in ICH patients than in LI patients (22.2% vs. 15.4%, 50% vs. 34% respectively, P>0.005). The frequency of bilateral cotton wool spots and of bilateral retinal haemorrhages was significantly higher in ICH patients than in LI patients (12.5% vs. 0%, P=0.012, 41.2% vs. 7.7%, P=0.029 respectively). CONCLUSION: These results confirm the high frequency of microvascular alterations in patients with hypertension-related SVD leading to LI or ICH and suggest that retinal tissue alterations are more frequent in ICH than in LI. Further investigations are needed to investigate the mechanisms underlying this difference.

Hypoglycaemia is associated with the absence of a decrease in diurnal macular thickness in patients with diabetic macular oedema.

AIM: Spontaneous diurnal variations measured by optical coherence tomography (OCT) have been reported in diabetic macular oedema (DME) together with a daytime decrease in central macular thickness (CMT). For this reason, this study aimed to investigate the influence of acute glucose and blood pressure changes on daytime variations in CMT in patients with DME. METHODS: In this prospective observational study of type 1 (n=4) and type 2 (n=18) diabetic patients with DME, OCT scans, capillary blood glucose, and systolic and diastolic blood pressure measurements were performed at 9 a.m., 12 a.m., 3 p.m., 6 p.m. and again at 9 a.m. the day after. At the same time, the study protocol included simultaneous ambulatory blood pressure and glucose monitoring over a 24-h period. Hypoglycaemic episodes, defined as glucose values<60mg/dL, were also recorded. RESULTS: CMT decreased consistently between 9 a.m. and 6 p.m. in 10 patients (from 374±82µm to 337±72µm; P=0.01) and increased or remained steady in 12 others (from 383±136µm to 390±149µm; P=0.58), with a significant difference in CMT absolute change between the two groups (P<0.001). In the study population as a whole, the lower the mean diurnal blood glucose, the smaller the decrease in CMT during the day (P=0.027). Also, eight (67%) of the 12 patients with a flat CMT profile experienced a diurnal hypoglycaemic event whereas none of those with a CMT decrease had hypoglycaemia (P=0.002). CONCLUSION: Hypoglycaemic events may explain the lack of diurnal CMT decrease in diabetic patients with DME. However, further studies need to be conducted to evaluate whether having no diurnal CMT decrease is associated with a poorer visual prognosis and whether it can be modified by better glucose control.

Ophdiat(®): five-year experience of a telemedical screening programme for diabetic retinopathy in Paris and the surrounding area.

AIM: This report describes our 5 years of experience with the ophthalmological diabetes telemedical network Ophdiat(®), designed to screen for diabetic retinopathy. METHODS: Seventeen hospitals, 11 primary healthcare centres and two prisons in the Paris area were gradually equipped with a non-mydriatic funduscopic camera between June 2004 and December 2009. Photos were taken by trained orthoptists and nurses, and interpreted by an average of seven certified ophthalmologists. The software was updated twice in 2008. RESULTS: In all, 38,596 patients were screened during 51,741 examinations between June 2004 and December 2009. Of these patients, 13,726 (26.55%) were referred to an ophthalmologist because of unreadable photographs (9.94%), advanced stages of retinopathy (14.71%) or concomitant eye diseases (1.90%). Patients screened in hospitals and prisons exhibited a greater prevalence of retinopathy and at more advanced stages. CONCLUSION: Telemedicine is a screening method that is well adapted for diabetic patients. In view of the increasing number of such patients and the decreasing number of ophthalmologists, expansion of the Ophdiat(®) screening network is desirable.

Evaluation of automated fundus photograph analysis algorithms for detecting microaneurysms, haemorrhages and exudates, and of a computer-assisted diagnostic system for grading diabetic retinopathy.

AIMS: This study aimed to evaluate automated fundus photograph analysis algorithms for the detection of primary lesions and a computer-assisted diagnostic system for grading diabetic retinopathy (DR) and the risk of macular edema (ME). METHODS: Two prospective analyses were conducted on fundus images from diabetic patients. Automated detection of microaneurysms and exudates was applied to two small image databases on which these lesions were manually marked. A computer-assisted diagnostic system for the detection and grading of DR and the risk of ME was then developed and evaluated, using a large database containing both normal and pathological images, and compared with manual grading. RESULTS: The algorithm for the automated detection of microaneurysms demonstrated a sensitivity of 88.5%, with an average number of 2.13 false positives per image. The pixel-based evaluation of the algorithm for automated detection of exudates had a sensitivity of 92.8% and a positive predictive value of 92.4%. Combined automated grading of DR and risk of ME was performed on 761 images from a large database. For DR detection, the sensitivity and specificity of the algorithm were 83.9% and 72.7%, respectively, and, for detection of the risk of ME, the sensitivity and specificity were 72.8% and 70.8%, respectively. CONCLUSION: This study shows that previously published algorithms for computer-aided diagnosis is a reliable alternative to time-consuming manual analysis of fundus photographs when screening for DR. The use of this system would allow considerable timesavings for physicians and, therefore, alleviate the time spent on a mass-screening programme.

Benefits of Ophdiat, a telemedical network to screen for diabetic retinopathy: a retrospective study in five reference hospital centres.

AIM: One objective of Ophdiat, a telemedical network using digital non-mydriatic cameras in Ile-de-France, is to develop a comprehensive screening programme that provides access to annual fundus examinations to all diabetic patients. The aim of this study was to evaluate the benefits of this programme in a hospital setting. METHODS: A retrospective analysis of 500 case reports of diabetic patients hospitalized before and after Ophdiat setup was performed in five reference hospital centres. At each centre, 100 case reports (50 before, 50 after) of patients aged greater than 18 years, hospitalized for their annual check-up, with no known diabetic retinopathy (DR) before hospitalization and with the last fundus examination performed greater than 11 months previously, were randomly selected. The primary endpoint was the proportion of patients whose fundus examinations were performed during hospitalization; secondary endpoints were the number of cases of DR found and the time taken by ophthalmologists to make the diagnosis. RESULTS: The mean proportion of patients with fundus examinations was 50.4% and 72.4% before and after, respectively, Ophdiat (P<0.01). The prevalence of DR was 11.1% before and 12.7% after (not significant). The mean time taken by an ophthalmologist per diagnosis of DR was 0.90 half-day before and 0.32 half-day after Ophdiat. CONCLUSION: This evaluation shows that Ophdiat, combined with the availability of modern and effective devices, has improved DR screening in diabetology departments in hospitals. Additional human resources would certainly ensure more effective use of the system.

OPHDIAT: a telemedical network screening system for diabetic retinopathy in the Ile-de-France.

OBJECTIVE: International and national guidelines recommend an annual funduscopic examination for all diabetic patients, but such annual fundus examinations are not sufficiently performed in France. Non-mydriatic fundus photography is a valid method of evaluation for diabetic retinopathy (DR) and a viable alternative to ophthalmoscopy. After two pilot studies demonstrated the feasibility of telemedical screening for diabetic retinopathy in both hospital and primary-care settings, we developed a regional telemedical network, OPHDIAT, designed to facilitate access to regular annual evaluations of patients with diabetes while saving medical time. MATERIALS AND METHODS: OPHDIAT comprises peripheral screening centres equipped with non-mydriatic cameras, where fundus photographs are taken by technicians linked by telemedicine to a reference centre, where ophthalmologists grade the images. Currently in the Ile-de-France region, 16 screening centres are linked through a central server to an ophthalmologic reading centre and includes 11 centres located in the diabetes departments of 11 hospitals, one diabetic retinopathy screening centre located in northern Paris, three in healthcare centres and one in a prison. RESULTS: During the 28-month evaluation period, 15,307 DR screening examinations were performed. Retinal photographs of at least one eye could not be graded in 1332 patients (9.7%) and diabetic retinopathy was detected in 3350 patients (23.4%). After the screening examination, 3478 patients (25.2%) were referred to an ophthalmologist for either DR, cataract and/or non-gradable photographs. CONCLUSION: Fundus photography combined with telemedicine has the potential to improve the regular annual evaluation for diabetic retinopathy. The organization of the network around a central reading centre serves to guarantee quality control.

OPHDIAT: quality-assurance programme plan and performance of the network.

AIMS: There is a need for evaluation of screening and grading services for diabetic retinopathy (DR) in compliance with quality-assurance (QA) standards. We describe the screening/grading QA programme set up for OPHDIAT over the 2005-2006 period. METHODS: Screening and grading objectives, evaluation criteria and minimum acceptable QA standards were set. To ensure the quality of DR photos, the proportion of nongradable photos in at least one eye had to be less than 10%. To ensure grading accuracy, intergrading agreement had to be greater than 90%. Grader-generated reports had to be available in less than 48 h for more than 80% photos. Readers had to grade 500 to 3000 photos per year. RESULTS: Sixteen screening centres were opened between June 2004 and December 2006, and 14,769 patients were screened. Percentages of nongradable photos were consistently below the QA requirement (less than 10%). Overall, 800 photos were graded a second time by a reader blinded to original grading; agreement between graders ranged from 92 to 99%. More than 90% of grader-generated reports were produced within 48 h. The number of readings by each grader nearly achieved the QA standard. CONCLUSION: QA for DR telescreening should be a continuous process to provide performance feedback, thus guaranteeing a high standard for delivered results. Almost all of the predetermined QA standards in OPHDIAT for screening and grading were met. Besides the quality/sensitivity of the screening/grading modalities, it is important to evaluate at-risk patients so that they can be treated efficiently; this should be addressed in a global QA programme.

[A new grading system from color fundus photographs for screening for diabetic retinopathy]. / Classification simplifiée de la rétinopathie diabétique adaptée au dépistage par photographies du fond d'oeil.

AIM: Fundus photographs using a nonmydriatic digital camera are the reference method for diabetic retinopathy screening today. The aim of this study was to validate a simplified diabetic retinopathy classification, adapted for diabetic retinopathy screening, including all diabetic retinopathy severity scales. PATIENTS AND METHODS: One hundred and twenty-one diabetic patients had three digital color fundus photographs taken, which were graded by four independent ophthalmologists according to the proposed screening classification, and a reference examination (nine field fundus photographs and optical coherence tomography examination of the macula). RESULTS: The proposed diabetic retinopathy screening classification was easy to use, as it was based on a visual comparison between the three digital color fundus photographs and standard retinal photographs. This classification provided the diagnosis of severe levels of diabetic retinopathy with high sensitivity and accurate specificity (100% and 50%-58%,respectively, for a moderate nonproliferative diabetic retinopathy level or higher on the screening examination) and the diagnosis of macular edema with a high sensitivity and specificity (96%-97% and 89%-91%, respectively). The results of the screening examination using this classification were highly reproducible (weighted k for interobserver agreement: 0.78-0.93). CONCLUSION: These results suggest that this new simplified classification is accurate. The screening method should not be used above the threshold level of mild nonproliferative diabetic retinopathy. Thus, from the moderate nonproliferative level (inclusive), a complete fundus examination should be undertaken. Severe levels of diabetic retinopathy will be referred to an ophthalmologist without delay for laser treatment.

Prevalence of diabetic retinopathy in children and adolescents with type-1 diabetes attending summer camps in France.

OBJECTIVE: To evaluate, using fundus photography, the prevalence of diabetic retinopathy (DR) in young diabetic subjects attending summer camps run by the Aide aux Jeunes Diabétiques Association (Aid to Young Diabetics). RESEARCH DESIGN AND METHODS: Five hundred and four children and adolescents (250 boys and 254 girls), with type 1 diabetes mellitus, aged 10-18 years (mean:13+/-2), were screened for DR using non mydriatic photography, during their stay in a holiday camp. Demographic and clinical data recorded on subjects' arrival in the camp included date of birth, height, weight, treatment, blood pressure, and duration of diabetes. HbA(1c) was determined with a DCA 2000 kit. RESULTS: Mean diabetes duration was 4.8+/-3.4 years and mean HbA(1c) was 8.5+/-1.3%. Mild non proliferative DR was diagnosed in 23 children (4.6%). Compared to subjects without DR, those with DR were significantly older (P<10(-3)), had a longer duration of diabetes (P=0.001), higher systolic blood pressure (P=0.04), and had higher (but not significantly so) HbA(1c) (P=0.15). After adjustment for age, only longer duration remained significantly associated with DR (P=0.01). CONCLUSION: The prevalence of DR in these young patients was low compared to that reported in previous studies. The decrease may be due to modern diabetes care with multiple insulin injections. However, early detection of DR in adolescents, especially in their late teens, remains important, because it allows the identification of patients at high risk of progression towards severe stages of DR.

Evaluation of the effect of JPEG and JPEG2000 image compression on the detection of diabetic retinopathy.

AIMS: To compare the effect of classic Joint Photographic Experts Group (JPEG) and JPEG2000 compression algorithms on detection of diabetic retinopathy (DR) lesions. METHODS: In total, 45 colour fundus photographs obtained with a digital nonmydriatic fundus camera were saved in uncompressed Tagged Interchanged Files Format (TIFF) format (1.26 MB). They were graded jointly by two retinal specialists at a 1 month interval for soft exudates, hard exudates, macular oedema, newvessels, intraretinal microvascular abnormalities (IRMA), and retinal haemorrhages and/or microaneurysms. They were compressed to 118, 58, 41, and 27 KB by both algorithms and 24 KB by classic JPEG, placed in random order and graded again jointly by the two retina specialists. Subjective image quality was graded, and sensitivity, specificity, positive and negative predictive values, and kappa statistic were calculated for all lesions at all compression ratios. RESULTS: Compression to 118 KB showed no effect on image quality and kappa values were high (0.94-1). Image degradation became important at 27 KB for both algorithms. At high compression levels, IRMA and HMA detection were most affected with JPEG2000 performing slightly better than classic JPEG. CONCLUSION: Performance of classic JPEG and JPEG2000 algorithms is equivalent when compressing digital images of DR lesions from 1.26 MB to 118 KB and 58 KB. Higher compression ratios show slightly better results with JPEG2000 compression, but may be insufficient for screening purposes.

Evaluation of a screening program for diabetic retinopathy in a primary care setting Dodia (Dépistage ophtalmologique du diabète) study.

OBJECTIVES: The aim of this observational study was to evaluate the screening for diabetic retinopathy (DR) using eye fundus photography taken by a nonmydriatic camera and transmitted trough the Internet to an ophthalmological reading centre, as compared to a dilated eye examination performed by an ophthalmologist. METHODS: A total of 456 and 426 diabetic patients were included by two different groups of primary care physicians (PCPs), 358 being screened with the non-mydriatic camera (experimental group) and 320 with dilated eye fundus exam (control group). RESULTS: The proportion of screened patients for whom PCPs received a screening report within the 6-month follow-up period was 74,1% for the experimental group and 71,5% for the control group. Screening for DR was negative in 77,6% of patients with eye fundus photographs vs 89,6% with dilated eye examination. DR was diagnosed in 62 patients (17,3%) with eye fundus photographs versus 31 with dilated eye examination (10,4%). Referral to an ophthalmologist was required in 59 reports of patients with photographs (16.5%), 23 of them due to high grade DR. Finally, the non-mydriatic camera was found of little inconvenience by patients. CONCLUSION: The telemedical approach to DR screening proved to be effective in providing primary care practitioners with information about their patient's eye status. This screening method allowed to identify patients requiring prompt referral to the ophthalmologist for further complete eye examination. In conclusion, this study provided successful results of DR screening using fundus photography in primary care patients, and strongly supports the need to further extend this screening program in a larger number of French sites.

Screening for diabetic retinopathy: the first telemedical approach in a primary care setting in France.

OBJECTIVES: Diabetic retinopathy (DR) remains a major cause of visual impairment in France, due to insufficient regular annual screening. Fundus photography is a sensitive alternative to ophthalmoscopy for DR screening. The aim of our study was to report the first telemedical approach to this screening in a primary care setting in France. METHODS: A DR screening centre equipped with a nonmydriatic camera was opened in the 18th district of northern Paris and placed at the disposal of general practitioners (GPs) of the Réseau de Santé Paris Nord (North Paris Health Network). These GPs were invited to send their diabetic patients who had no known DR and had had no fundus examination for more than one year to this screening center. Retinal photographs were taken by an orthoptist without pupillary dilation and sent for grading through the Internet to the Lariboisière Hopital Ophthalmology Department. RESULTS: During an 18-month period, 912 DR screening examinations were performed in 868 diabetic patients referred to the DR screening center by 240 GPs. Patients' mean +/- SD age was 59.9 +/- 11.1 years. Of these 868 patients, 260 (30%) said they never have had an ophthalmological examination. Diabetic retinopathy was detected in 197 patients (22.7%). The proportion of patients for whom fundus photographs of one or both eyes could not be assessed was 10.1%. 159 patients (18.3%) required referral to an ophthalmologist. CONCLUSION: Nonmydriatic photography, combined with teletransmission to a reading centre, proved to be a feasible valid method for the detection of DR. This screening method allowed the identification of patients requiring prompt referral to an ophthalmologist for further complete eye examination.

[Diabetic retinopathy in children and adolescents]. / La rétinopathie diabétique du sujet jeune: l'enfant et l'adolescent.

Diabetic retinopathy rarely occurs before puberty and is never proliferative in prepubescent children. On the opposite, puberty and adolescence are high-risk periods for diabetic retinopathy progression, and call for strict ophthalmologic monitoring. The period between 16 and 18 years of age is particularly critical. Progression towards florid diabetic retinopathy is to be especially feared and should be prevented in the course of adolescence, as this form can be severe and can lead to blindness. Risk factors are probably many, including diabetes duration, difficulties in achieving glycemic control due to increase in insulin requirements, low compliance to treatment, and hormonal changes related to puberty (abnormalities of the growth hormone (GH)/insulin-like growth factor-I (IGF-1) axis). Systematical diabetic retinopathy screening should be performed in adolescents, notably by non-mydriatic fundus photographs. Furthermore, the anticipation of the switch from pediatric to adult structures, together with the careful information and education of parents and children may improve visual prognosis of young diabetic patients, whose life expectancy is high.

Evaluation of a new non-mydriatic digital camera for detection of diabetic retinopathy.

AIMS: To compare the results of fundus photography using a new non-mydriatic digital camera with the results of reference standard of Early Treatment Diabetic Retinopathy Study (ETDRS) retinal photographs, for the detection of diabetic retinopathy (DR). METHODS: Fundus colour photographs were taken with a Topcon non-mydriatic camera of 147 eyes of 74 diabetic patients, without pupillary dilation (five overlapping fields of 45 degrees; posterior pole, nasal, temporal, superior and inferior). Three retinal specialists classified the photographs in a masked fashion, as showing no DR or mild non-proliferative DR (NPDR) not requiring referral, moderate or more severe NPDR and/or macular oedema, or as non-gradable image requiring referral. ETDRS 35-mm colour slides served as reference images for DR detection. RESULTS: For moderately severe to severe DR, the sensitivities of detection reported by the three observers were 92, 100 and 92%, respectively, and the specificities, 87, 85, and 88%. For four levels of DR severity (none or mild NPDR, moderate NPDR, severe NPDR and proliferative DR), the percentages of exact agreement between the three observers on the retinopathy grades assigned to the non-mydriatic photographs and to the ETDRS reference slides were 94.6, 93 and 87.6%, respectively (kappa 0.60-0.80). Sixteen eyes of nine patients (11%) were judged ungradable by at least one observer. In a second series of 110 patients, evaluated in the setting of a screening procedure, fewer photographs were ungradable (< 6%). CONCLUSION: These results suggest that fundus photographs taken by the Topcon TRC-NW6S non-mydriatic camera, without pupillary dilation, are suitable for DR screening.

Retinal thickness in healthy and diabetic subjects measured using optical coherence tomography mapping software.

PURPOSE: To define the normal retinal thickness in healthy subjects using optical coherence tomography (OCT) mapping software and to assess the ability of OCT to detect early macular thickening in diabetic patients. METHODS: Six radial scans centered on the fixation point were done on 60 healthy eyes and 70 eyes of 35 diabetic patients without macular edema on biomicroscopy. Retinal thickness was measured automatically with OCT mapping software. Mean retinal thickness was compared in subgroups of healthy patients based on age, sex, and eye, and in the eyes of diabetic patients and healthy subjects. Thickening was diagnosed if mean retinal thickness of an area was greater than the mean thickness + 2SD in the corresponding area in healthy subjects; or if the difference between right and left eye exceeded the mean difference + 2 SD in a given area in healthy subjects. RESULTS: In healthy subjects, mean retinal thickness in the central macular area 1000 microm in diameter was 170+/-18 microm. There was no significant difference according to age, or left or right eye, but central macular thickness was significantly greater in men than women (p=0.0139). No difference was observed between the eyes of healthy subjects and diabetic patients without macular edema on biomicroscopy, but OCT detected early macular thickening in 12 diabetic eyes. CONCLUSIONS: In this study average retinal thickness and mean local variations in a normal population were defined using a commercially available mapping software. OCT seems a sensitive tool for detecting early retinal thickening.

Reproducibility of retinal mapping using optical coherence tomography.

OBJECTIVE: To assess the reproducibility of retinal thickness measurement using commercially available mapping software of optical coherence tomography (OCT). METHODS: Six radial scans, 6 mm long and centered on the fixation point, were performed on 10 eyes of 10 healthy volunteers and 10 eyes of 10 diabetic patients with clinically significant macular edema. Retinal thickness was measured automatically using the mapping software of OCT in the 9 macular Early Treatment Diabetic Retinopathy Study areas and in a central area 500 microm in diameter. Measurement reproducibility was tested by means of 3 series of scans performed by 2 different observers on 2 different days. Results were assessed by their repeatability and intraclass correlation coefficients (ICCs). RESULTS: In healthy subjects, intraobserver, interobserver, and intervisit reproducibility of retinal thickness measurements were excellent, with a repeatability coefficient of less than 7 microm and ICCs of greater than 0.89. In diabetic patients, the repeatability coefficient was less than 21 microm in all areas of the macula except one, with an ICC of greater than 0.98. Relative variations in measurements were small in both healthy and diabetic subjects, with reproducibilities of +/- 5% and +/- 6%, respectively. CONCLUSION: Retinal mapping software of OCT allows reproducible measurement of retinal thickness in both healthy subjects and diabetic patients with macular edema.